ui(lint): adopt ui.* components, colors, and outcome glyphs instead of [MISS]/=== format

[codeaholicguy]

Current output

=== Base Structure ===
[MISS]  docs/ai/requirements/README.md
       Run: npx ai-devkit@latest init
[MISS]  docs/ai/design/README.md
       Run: npx ai-devkit@latest init
...

5 required check(s) failed.

Problems

1. Completely different visual language from the rest of the CLI: === Base Structure === headers and [MISS] tags use no ui.* components, no color, and no glyphs — every other command uses bold headers, ✔/⚠/✖ prefixes, and colored statuses. lint output looks like a different tool.
2. No color anywhere: [MISS] (required failure), warning-level checks, and the pass state are visually identical; the severity mapping only exists in LINT_STATUS_LABEL.
3. Summary line has no outcome signal: All checks passed. and 5 required check(s) failed. are plain text — no ✔/✖ glyph, no green/red, though this is the single most important line for CI and humans.
4. Naive pluralization: check(s) failed., warning(s) reported.
5. Magic 7-space fix indentation: Run: npx ai-devkit@latest init aligns to a hand-counted offset that breaks if LINT_STATUS_LABEL widths change; no dim styling to de-emphasize the hint.
6. === decoration collides with the bold-header convention used by channel list (Configured Channels:), status, and agent list.

Expectation

Base Structure
  ✖ docs/ai/requirements/README.md
    Fix: npx ai-devkit@latest init

✔ All checks passed.

• Route output through ui.* (ui.table or styled ui.text): bold section titles (no ===), colored status glyphs (✖ red for required misses, ⚠ yellow for warnings, ✔/dim for passes when not --quiet).
• Fix hints on their own dim line with a Fix: prefix — indentation derived from the glyph column, not a literal.
• Pluralized summary via the shared helper, colored by outcome, with the existing exit-code behavior unchanged (process.exitCode = report.exitCode).
• Keep --json output byte-identical (it is already a separate branch).

Files: packages/cli/src/commands/lint.ts (renderLintReport, printSection, printRows), packages/cli/src/services/lint/constants.ts (LINT_STATUS_LABEL)